NEW YORK -- New York's top attorney is stepping down after four women accused him of abuse.

• 4 former lovers accused Attorney General Eric Schneiderman of physical abuse
• NY governor wants criminal investigation
• Schneiderman's ex- wife comes to his defense

The accusations against Attorney General Eric Schneiderman is taking many people by surprise because this is a man who stood up for women's rights. 

He advocated for stricter gun laws after the shooting in Parkland Florida and he has been a champion of the #metoo movement.

However, Schneiderman is being accused of abusive behavior against four women he was romantically involved with.

The New Yorker spoke to those women, who say Schneiderman, a Democrat, choked and slapped them and even threatened them.

After the story broke, he announced his resignation but also denied the allegations.

"While these allegations are unrelated to my professional conduct or the operations of the office, they will effectively prevent me from leading the office's work at this critical time," he said in a statement. "I therefore resign my office, effective at the close of business on May 8, 2018."

Sources tell NY1 that Solicitor General Barbara Underwood will take over for the office when Schneiderman steps down Tuesday.

Late Monday night, the Manhattan district attorney's office said it has opened an investigation into the allegations against Schneiderman.

Schneiderman's announced resignation came less than two hours after New York Gov. Andrew Cuomo said he would ask for a criminal investigation into Schneiderman, and called on him to resign.

In a statement, Cuomo said, "No one is above the law, including New York's top legal officer.  I will be asking an appropriate New York District Attorney to commence an immediate investigation, and proceed as the facts merit. My personal opinion is that, given the damning pattern of facts and corroboration laid out in the article, I do not believe it is possible for Eric Schneiderman to continue to serve as Attorney General, and for the good of the office, he should resign."

It was all the fallout of four women who have had romantic relationships with Schneiderman -- whose office has taken on a high-profile role in the fight against sexual misconduct -- accusing him of physically abusing them.

Those women said Schneiderman repeatedly hit them during the course of their relationships with him in recent years, and never with their consent. Neither woman filed any police complaints, but both said they sought out medical attention and confided in people close to them about the abuse. The New York Police Department said it has no complaints on-file but would investigate thoroughly if it receives any.

A third woman who also was involved with him told her story to the other two women, but said she was too frightened to come forward. A fourth woman said Schneiderman slapped her when she rebuffed him, but also asked to remain unidentified. The New Yorker said it vetted the third woman's allegations, and saw a photo of what the fourth woman said was her injury.

The two women who spoke on the record, Michelle Manning Barish and Tanya Selvaratnam, both said the physical abuse escalated over time, including choking and hitting, and that Schneiderman also was a heavy drinker. The Associated Press and Spectrum News are identifying the women because they agreed to tell their stories publicly.

Manning Barish said she was involved with Schneiderman from mid-2013 through the end of 2014; Selvaratnam said she was involved with him from the summer of 2016 until fall 2017.

Manning Barish said Schneiderman started getting violent a few weeks after they began dating, slapping her one night after an evening out and escalating to choking her. She said she confided in friends, including novelist Salman Rushdie.

Selvaratnam said Schneiderman warned her he could have her followed or her phones tapped. Both said he threatened to kill them if they broke up with him.

Asked for comment before he announced he would resign, Schneiderman issued a statement saying, "In the privacy of intimate relationships, I have engaged in role-playing and other consensual sexual activity. I have not assaulted anyone. I have never engaged in non-consensual sex, which is a line I would not cross.''

In a statement earlier Monday night, Schneiderman's ex-wife Jennifer Cunningham defended Schneiderman.

"I've known Eric for nearly 35 years as a husband, father and friend. These allegations are completely inconsistent with the man I know, who has always been someone of the highest character, outstanding values and a loving father. I find it impossible to believe these allegations are true," she stated.

The Associated Press and Spectrum News contributed to this story.